Medicine: Those Amazing Chemical Scissors

Because the basic blueprint of human life is encoded in hundreds of
thousands of genes contained in unwieldy strands of DNA in each living
cell, researchers have had a hard time deciphering it. But in recent
years they have been greatly aided in their work by a group of
remarkable tools: enzymes that act as chemical scissors, cutting strips
of DNA into precise and manageable fragments.

The discovery of these so-called restriction enzymes promises to help un
ravel the mysteries of cell development, hereditary disease and...